Dear Editor,
I am pleased my letter on the Dryhead Agate has been published. This makes it clear that ordinary banded agates are colloidal in origin and not formed from solution as suggested
previously, before a low temperature was established by the isotope results. These indicate agate formation took place at 50°C.
Mexican Coconuts are the agates for which most data exist being the subject of a thesis. A recent study of rocks in Skye provides information on the bentonite, the mineralogy of which is relevant.
The bentonite includes colloidal silica as well as montmorillonite, a clay mineral. It will be present in Mexico as well as at the base of the Skye lava field and is the obvious source of any agates present.
J. Jocelyn
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Dear Editor,
I was disappointed to here that the B.L.M.D.A (British Lapidary & Mineral Dealers Association) has now closed. I regularly attended their shows in particularly the Harrogate show.
As there are many mineral dealers in the country will a new association be formed and what will happen to the shows?
Best wishes
R. Page
Editors response
Yes we were also saddened to here that the B.L.M.D.A has closed, I believe the current chair person retired. Hopefully some of the dealers will get together to form a new organisation and look at reinstating the shows. However I was informed that Keith & Carol from Rock & Gem Ltd had booked the Harrogate venue to put on a Rock Gem 'n' Bead show this year.
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